<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      width: 100vw;
      background-color: black;
      height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    
    .container {
      width: 100px;
      height: 100px;
      border: 4px solid aquamarine;
      background-color: #222;
      overflow: hidden;
      border-radius: 50%;
      font-size: 36px;
      filter: blur(6px) contrast(6); /* 主要靠这行代码 */
      display: flex;
      justify-content: center;
      align-items: center;
    }
    
    .box {
      width: 1em;
      height: 1em;
      transform: translate(0px, 0px);
      background-color: aquamarine;
      animation: move 2s linear infinite;
    }
    
    @keyframes move {
      from {
        transform: translateX(-100px);
      }
    
      to {
        transform: translateX(100px);
      }
    }
  </style>
</head>

<body>
  <div class="container">
    <div class="box"></div>
  </div>
</body>

</html>